Yes, wear tape is a thin film of UHMW with adhesive backing than can be bonded to the surface. UHMW can be made in films. Tolerance levels are dependent on the manufacturing method and part design. Contact us for specific technical data. Yes, again the process is much like regular HDPE. If the plastic is softer, like UHMW, more attenuation of the ultrasonic energy occurs.
Yes, it behaves much like regular HDPE. The minimum temperature is degrees F and the minimum pressure of psi is highly recommended. Not for most applications. The reason is the large d ifference between the coefficient of thermal expansion of metal and UHMW puts high stresses on the bond if the bond encounters temperature extremes.
There are two methods of adhering — the use of pressure sensitive systems peel and stick and allowing UHMW-PE to be bonded using epoxy systems or contact cements. A traditional metal mechanical fastening can also be used if preferred. Bending or folding sheet can be done efficiently above the melt point at degrees F.
At that temperature, it shapes easily. However, it must be fastened in the bent or folded position until cooled. The liner should be thicker in impact areas and thinner in slide areas.
Important notes: UHMW cannot be firmly fastened to metals because of a large difference in thermal expansion. UHMW expands five times as fast as steel and three times as fast as aluminum and about the same as wood but slightly more than concrete. Fasteners are the best way to secure UHMW to metal. The UHMW must be allowed to expand or float. Large flat head fasteners must be used.
Fastener shaft holes in UHMW must be over-sized to allow for sheet expansion and contraction. Back to Materials. Where is UHMW used? There are three tests you can perform: Burn Test — light it with a match and smell the smoke. If it smells like candle wax — that indicates polyethylene. Oven Test — place it in an aluminum dish in a degree oven.
However, it could warp or distort due to built in stresses. What is the temperature range of UHMW? What are the heat characteristics of UHMW? The only way to know if it can be welded is to try it. You can use compressed air to weld UHMW but this does produce smoke and ventilation is required. Nitrogen can also be used and it will not produce smoke. Both air and nitrogen will produce the same quality weld. You will need a 20 AMP circuit, volt.
Activate the pressure switch by turning the air pressure to between 8 — 10 PSI. The welder will take about 7 minutes to completely heat up. The parts to be welded must be beveled or have a fillet. Its small size and light weight make it possible to weld in a wide variety of set-ups from tight areas to in-shop or on-site repairs and fabrication. So proper preparation is key. The weld area must be clean and, depending on the weld design, the material may need to be beveled out to weld to the root.
The pre-heater has an open flame. This requires special handling in order to keep the equipment safe. The distances of the flame to the tip and flame to the parent material are important. When the flame comes in contact with the parent material, the welding process needs to start immediately to avoid damaging it.
In conclusion, whatever type of welding your shop is doing, proper training is essential to consistently producing quality welds. Plastic welding will be easier if you are trained in the proper techniques, understand the importance of the three welding parameters, know the application, know the material and know the welding system.
Bramer has been working since with a wide variety of plastic materials and equipment. His background includes three years apprenticeship training as a plastic fitter, two years school for Plastic Master Technician and supervisor for a plastic shop in Germany, where he also received his DVS plastic welding certificates.
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